The Crown Office has now concluded that there should be "no criminal proceedings at this time".

It said this was due to an "absence of sufficient credible and reliable evidence", with the decision coming after "careful consideration of the facts and circumstances of the case".

Mrs Thomson had always strongly denied any wrongdoing.

'Completely exonerated'

The former Edinburgh West MP had been one of five people named in the report sent by Police Scotland to the procurator fiscal.

It is understood one of the men named in the report was solicitor Christopher Hales, who was struck off by the Law Society after being found guilty of professional misconduct over 13 property deals in 2010 and 2011.

All 13 of the transactions Mr Hales was struck off for were reported to have involved Mrs Thomson or M&F Property Solutions, a firm in which she was said to be a partner.

In a statement released on Tuesday afternoon, Ms Thomson said: "Yesterday I received news from the Crown Office that confirmed I have been completely exonerated by the police investigation into a solicitor I used in 2010.

"I am eternally grateful to my SNP colleagues in Westminster who supported me so strongly throughout this time.

"I also thank Police Scotland and the Crown Office for their courtesy and professionalism."

'Next steps'

She added: "I made clear before I entered politics that I wished to use my skills, drive and experience to help shape a better Scotland, and that desire remains as strongly as it did when I became very involved in the 2014 independence referendum.

"However, for the time being this will need to take a different form. I now intend to take a few days of reflection to consider my next steps."

A Crown Office spokesman said: "The procurator fiscal received a report concerning four men aged 48, 56, 59 and 59, and one woman aged 51, in relation to alleged incidents between June 16 2010 and July 26 2011.

"After careful consideration of the facts and circumstances of the case, Crown counsel concluded there was an absence of sufficient credible and reliable evidence and there should be no criminal proceedings at this time."

Mrs Thomson, who was elected in 2015, had been sitting as an independent MP after resigning from the SNP whip.

Her former SNP colleagues gave their unanimous backing in September to calls for the party to consider reinstating her.

But she was told by the SNP's national executive in April that she would not be selected as a candidate in the election, with the party instead choosing Toni Giugliano to stand in Edinburgh West.

Mr Giugliano ultimately lost the seat to Christine Jardine of the Scottish Liberal Democrats.

A spokesman for the SNP said: "Ms Thomson took a dignified approach during the investigation into her financial conduct. She'll be relieved to put this affair behind her and we wish her well for the future."